Laser saddle for 990 Aftershock

[brian10x]

Just got one of the first Mossberg 990 Aftershocks here in Tucson, and I love the gun. I have the basic model, but I'd like to try the Crimson Trace laser saddle.
Does anyone know the part number that fits this gun? I've written Crimson Trace, but have yet to get an answer.

Thanks!